sqlite can be used in ios for handling data. it uses sqlite queries, which makes it easier for those who know sql.

steps involved

step 1 − create a simple view based application.

step 2 − select your project file, then select targets and then add libsqlite3.dylib library in choose frameworks.

step 3 − create a new file by selecting file→ new → file... → select objective c class and click next.

step 4 − name the class as dbmanager with "sub class of" as nsobject.

step 5 − select create.

step 6 − update dbmanager.h as follows −

#import <foundation/foundation.h>
#import <sqlite3.h>

@interface dbmanager : nsobject {
   nsstring *databasepath;
}

+(dbmanager*)getsharedinstance;
-(bool)createdb;
-(bool) savedata:(nsstring*)registernumber name:(nsstring*)name 
   department:(nsstring*)department year:(nsstring*)year;
-(nsarray*) findbyregisternumber:(nsstring*)registernumber;

@end

step 7 − update dbmanager.m as follows −

#import "dbmanager.h"
static dbmanager *sharedinstance = nil;
static sqlite3 *database = nil;
static sqlite3_stmt *statement = nil;

@implementation dbmanager

+(dbmanager*)getsharedinstance {
   if (!sharedinstance) {
      sharedinstance = [[super allocwithzone:null]init];
      [sharedinstance createdb];
   }
   return sharedinstance;
}

-(bool)createdb {
   nsstring *docsdir;
   nsarray *dirpaths;
   
   // get the documents directory
   dirpaths = nssearchpathfordirectoriesindomains
   (nsdocumentdirectory, nsuserdomainmask, yes);
   docsdir = dirpaths[0];
   
   // build the path to the database file
   databasepath = [[nsstring alloc] initwithstring: 
   [docsdir stringbyappendingpathcomponent: @"student.db"]];
   bool issuccess = yes;
   nsfilemanager *filemgr = [nsfilemanager defaultmanager];
   
   if ([filemgr fileexistsatpath: databasepath ] == no) {
      const char *dbpath = [databasepath utf8string];
      if (sqlite3_open(dbpath, &database) == sqlite_ok) {
         char *errmsg;
         const char *sql_stmt =
         "create table if not exists studentsdetail (regno integer 
         primary key, name text, department text, year text)";
         
         if (sqlite3_exec(database, sql_stmt, null, null, &errmsg) != sqlite_ok) {
            issuccess = no;
            nslog(@"failed to create table");
         }
         sqlite3_close(database);
         return  issuccess;
      } else {
         issuccess = no;
         nslog(@"failed to open/create database");
      }
   }    
   return issuccess;
}

- (bool) savedata:(nsstring*)registernumber name:(nsstring*)name 
   department:(nsstring*)department year:(nsstring*)year; {
   const char *dbpath = [databasepath utf8string];
   
   if (sqlite3_open(dbpath, &database) == sqlite_ok) {
      nsstring *insertsql = [nsstring stringwithformat:@"insert into
      studentsdetail (regno,name, department, year) values
      (\"%d\",\"%@\", \"%@\", \"%@\")",[registernumber integervalue],
      name, department, year];        
      const char *insert_stmt = [insertsql utf8string];
      sqlite3_prepare_v2(database, insert_stmt,-1, &statement, null);
      
      if (sqlite3_step(statement) == sqlite_done) {
         return yes;
      } else {
         return no;
      }
      sqlite3_reset(statement);
   }
   return no;
}

- (nsarray*) findbyregisternumber:(nsstring*)registernumber {
   const char *dbpath = [databasepath utf8string];
   
   if (sqlite3_open(dbpath, &database) == sqlite_ok) {
      nsstring *querysql = [nsstring stringwithformat:
      @"select name, department, year from studentsdetail where 
      regno=\"%@\"",registernumber];
      const char *query_stmt = [querysql utf8string];
      nsmutablearray *resultarray = [[nsmutablearray alloc]init];
      
      if (sqlite3_prepare_v2(database, query_stmt, -1, &statement, null) == sqlite_ok) {
         if (sqlite3_step(statement) == sqlite_row) {
            nsstring *name = [[nsstring alloc] initwithutf8string:
            (const char *) sqlite3_column_text(statement, 0)];
            [resultarray addobject:name];
            
            nsstring *department = [[nsstring alloc] initwithutf8string:
            (const char *) sqlite3_column_text(statement, 1)];
            [resultarray addobject:department];
            
            nsstring *year = [[nsstring alloc]initwithutf8string:
            (const char *) sqlite3_column_text(statement, 2)];
            [resultarray addobject:year];
            return resultarray;
         } else {
            nslog(@"not found");
            return nil;
         }
         sqlite3_reset(statement);
      }
   }
   return nil;
}

step 8 − update viewcontroller.xib file as follows −

step 9 − create iboutlets for the above text fields.

step 10 − create ibaction for the above buttons.

step 11 − update viewcontroller.h as follows −

#import <uikit/uikit.h>
#import "dbmanager.h"

@interface viewcontroller : uiviewcontroller<uitextfielddelegate> {
   iboutlet uitextfield *regnotextfield;
   iboutlet uitextfield *nametextfield;
   iboutlet uitextfield *departmenttextfield;
   iboutlet uitextfield *yeartextfield;
   iboutlet uitextfield *findbyregisternumbertextfield;
   iboutlet uiscrollview *myscrollview;
}

-(ibaction)savedata:(id)sender;
-(ibaction)finddata:(id)sender;
@end

step 12 − update viewcontroller.m as follows −

#import "viewcontroller.h"

@interface viewcontroller ()
@end

@implementation viewcontroller

- (id)initwithnibname:(nsstring *)nibnameornil bundle:(nsbundle *)
   nibbundleornil {
   self = [super initwithnibname:nibnameornil bundle:nibbundleornil];
   
   if (self) {
      // custom initialization
   }
   return self;
}

- (void)viewdidload {
   [super viewdidload];
   // do any additional setup after loading the view from its nib.
}

- (void)didreceivememorywarning {
   [super didreceivememorywarning];
   // dispose of any resources that can be recreated.
}

-(ibaction)savedata:(id)sender {
   bool success = no;
   nsstring *alertstring = @"data insertion failed";
   
   if (regnotextfield.text.length>0 &&nametextfield.text.length>0 &&
      departmenttextfield.text.length>0 &&yeartextfield.text.length>0 ) {
      success = [[dbmanager getsharedinstance]savedata:
      regnotextfield.text name:nametextfield.text department:
      departmenttextfield.text year:yeartextfield.text];
   } else {
      alertstring = @"enter all fields";
   }     
   
   if (success == no) {
      uialertview *alert = [[uialertview alloc]initwithtitle:
      alertstring message:nil
      delegate:nil cancelbuttontitle:@"ok" otherbuttontitles:nil];
      [alert show];
   }
}

-(ibaction)finddata:(id)sender {
   nsarray *data = [[dbmanager getsharedinstance]findbyregisternumber:
   findbyregisternumbertextfield.text];
   
   if (data == nil) {
      uialertview *alert = [[uialertview alloc]initwithtitle:
      @"data not found" message:nil delegate:nil cancelbuttontitle:
      @"ok" otherbuttontitles:nil];
      [alert show];
      regnotextfield.text = @"";
      nametextfield.text =@"";
      departmenttextfield.text = @"";
      yeartextfield.text =@"";
   } else {
      regnotextfield.text = findbyregisternumbertextfield.text;
      nametextfield.text =[data objectatindex:0];
      departmenttextfield.text = [data objectatindex:1];
      yeartextfield.text =[data objectatindex:2];
   }
}

#pragma mark - text field delegate
-(void)textfielddidbeginediting:(uitextfield *)textfield {
   [myscrollview setframe:cgrectmake(10, 50, 300, 200)];
   [myscrollview setcontentsize:cgsizemake(300, 350)];
}

-(void)textfielddidendediting:(uitextfield *)textfield {
   [myscrollview setframe:cgrectmake(10, 50, 300, 350)];

}

-(bool) textfieldshouldreturn:(uitextfield *)textfield {
   [textfield resignfirstresponder];
   return yes;
}
@end

output

when we run the application, we'll get the following output where we can add and find the student details −